Method and apparatus for processing strip material through treating units



Feb. 22, 1955 F. s. WEISER 2,702,766

METHOD AND APPARATUS FOR PROCESSING STRIP MATERIAL THROUGH TREATING UNITS Filed Oct. 21. 1950 4 She ets-Sheet l IGJ INVENTOR Franklin SWeiSer TTORNEY S. WEISER METHOD AND APPARATUS FOR PROCESSING STRIP MATERIAL THROUGH TREATING UNITS Filed Oct. 21. 1950 Feb. 22, 1955 4 Sheets-Sheet 2 INVENTOR Franklin 5. Weis er ATTORNEY Feb. 22, 1955 F. s. WEISER 2,702,766

METHOD AND APPARATUS FOR PROCESSING STRIP MATERIAL THROUGH TREATING UNITS Filed Oct. 21. 1950 4 Sheets-Sheet 3 INVENTOR Franklin S. Weiser y. a m

ATTORN EY Feb. 22, 1955 F. s. WEISER METHOD AND APPARATUS FOR PROCESSING STRIP MATERIAL THROUGH TREATING UNITS 4 Sheets-Sheet 4 Filed Oct. 21. 1950 INV ENTOR Franklin S.Weiser TTORNEY United States Patent METHOD AND APPARATUS FOR PROCESSING STRIP MATERIAL THROUGH TREATING UNITS Franklin S. Weiser, Cheshire, Conn, asslgnor to Scovill Manufacturing Company, Waterbury, Conn., a corporation of Connecticut Application October 21, 1950, Serial No. 191,460

7 Claims. (Cl. 134-15) This invention relates to a mechanism and to the art of processing strip material through various types of treating units such as washing, pickhng and drying machines.

Heretofore in treating strip material it has been customary to stop the material while part of It is In the machine in order to attach adjacent ends of the strips together as by a stapling or welding operation for the purpose of drawing the strips as a unit through the treating mechanisms. This process required a stoppage of the strip while the ends were being connected and n some constructions damage might be done to the strip while remaining at rest.

Also it is known that where there has been an attempt to keep the strip material constantly running through treating units, it has required either deep groundprts or elevating racks where provision is made for looping sections of the strips and then paying out the loops In the process of stopping the tail end of the stnp for the purpose of attaching another strip of material to the one being treated. This latter process has required an expensive mechanism and an excessive amount of room in order to provide sufficient space in wh ch to loop enough of the strip material to permit a portion of the strip to travel continuously through the treating units while the loops are paying off to allow sufiicient time to stop the tail end of the treated strip for the purpose of attaching it to the next adjacent strip tobe drawn through the machine.

A similar complication results at the dlscharge end of the machine. Either the strip must be stopped for a considerable time while the joint is being cut out and the leading strip on the blocker or roller removed and a new blocker put in place and the following strip directed thereinto; or if an attempt is made to run the strip continuously, a second large looping pit is required to take care of the material coming through while the joint is being cut and the blocker replaced.

It will thus be apparent to those skilled in the art that it would be a decided advantage to feed the strips through the process, one after the other, without splicing or otherwise attaching them together. Any suggestions of endless chains, cables or the like has not proven practical for this purpose for several reasons. The strip must be exposed to the action of the pickling liquid throughout its width, whereas chains and cables would interfere with the pickling action on the strips, and also the pickling would have a deleterious effect upon said chains and cables. My invention eliminates all of the above difliculties.

One of the objects of the invention is to provide an improved process and especially a pickling process in which long metal strips may be passed through the treating units without the necessity of splicing the strips together and without the necessity of interrupting either the movement of the strip or shutting ofi the treating units. This process involves the use of a leader or guide member attached to the leading end of each strip for guiding and drawing the strips through the units and results in much less waste of material ascompared to any splicing operation because the strip leader will not damage the metal, whereas when the strips are spliced a section must be cut out and scrapped.

Another object of this invention is to attach a leader bar of sufficient weight to the leading end of a strip of material to permit the bar to be propelled through the several treating units by power-driven rolls operating 2,702,766 Patented Feb. 22, 1955 2 within said units and then detaching the leader bar at the discharge end of the units and remove it from the path of the traveling strip while the latter will then be either processed through units by its own weight upon the power-driven rolls or by pinch feed rolls.

Another object of this invention is to provide a mechae nism wherein the leader bar can be immediately released from the leading end of the strip upon its emergence from the last treating unit and then causing the leader bar to travel at a speed in excess of the strip material to a position wherein the leader bar can be removed from the line of travel of the strip material without danger of interfering with the same.

Numerous other objects and, advantages of the invention will be apparent as it is better understood from the following description which taken in connection with the accompanying drawing discloses a preferred embodiment thereof.

Referring to the drawings:

Fig. 1 is a plan view of the strip DlSm.

Fig. 2 is a front elevation of the same, showing some of the electrical controls employed in the operation of the machine and the leader bar starting through the treating units.

treating unit mecha- Fig. 3 is a front elevation of the right end of the mechanism on an enlarged scale.

Fig. 4 is a cross section on line 4-4 the leader bar lifting unit.

Fig. 5 is a cross section on line 5--5 of Fig. 1 showing the leader bar loading unit.

Fig. 6 is a plan view of the leader bar unit, per se.

Fig. 7 is a left end view of the same.

Fig. 8 is a longitudinal section through the leader bar unit taken along line 8-8 of Fig. 6.

Fig. 9 is a rear view of one of the leader bar guide roller supports.

Fig. 10 is an end view of the same without the roller.

Fig. 11 is a vertical sectional view taken along line 11-11 of Fig. 9.

Fig. 12 is a side elevation view of the pinch roll unit.

Fig. 13 is a schematic view of the differential clutch control unit, and

Fig. 14 is a perspective view of a cam guide box for the hinging end of the leader bar return rail.

In showing one example as to how the leader bar is used in association with a treating unit for strip material,

of Fig. 1 showing I have shown the invention as applied to a pickling unit of a sheet metal machine with mechanisms for feeding and drawing the sheet material through the pickling unit. In referring to Figs. 1 and 2 a coil of sheet metal material or strip S is mounted upon a motor-driven pay-off" unit 10 by means of which an operator can slowly unroll or jog a coil around in directing its leading end into the machine. The leading end of the coil S is first directed into a pair of pinch feed rolls 11 attached to a straightener roll unit 12. The metal is then directed onto the rolls 13 of an entry table 14 where the material is stopped for the purpose of attaching a leader bar 15 to the leading end of the strip S. The details of the leader bar 15 and entry table 14 will be more fully explained later. The rolls 13 of the entry table 14 as well as all other units will be stopped during the attachment of the leader bar 15. With the bar 15 attached to the leading end of the strip S, the rolls 13 and 17 will be started up whereby the weight of the leader bar 15 itself resting upon at least two of the power-driven rolls 13 when in operation is suificient to draw the stock S across the entry table 14 toward the treating units of the machine. The leader bar is then led into a treating unit or any series of treating units, here shown as a portion of a pickling tank 16 having a series of support rolls 17 journaled therein.

The supporting rolls 17 as well as the rolls 13 on the entry table 14 are power driven through any suitable common drive such as sprockets on the end of the rolls and a sprocket chain so that the relatively heavy leader bar 15 resting on two or more of these rolls when in operation will exert a sufiicient pulling force on the strip to pull it into and through the several treating units from the pinch feed rolls 11. v

In the pickling tank 16 it is the general practice to have the picklm solution sprayed against opposite sides of the strip S as by spray nozzle 18 and then have the greater portion of the pickling solution cleaned from the strip by air jet nozzles 19. Other treating units may be incorporated in the line such as a bichromat1c wash tank, a rinse tank, a drying tank, etc., all known 1n the art of metal treating.

As soon -as the leader bar 15 emerges from the r ght or discharge end of the last treating unlt, 1t trips a l mit switch L. S. 2 and then immediately passes through a pinch feed roll unit- 20, the rolls of WhlCh at this time will be spaced to permit the leader bar to freely pass therethrough and from there on to the rolls 21 of a runout table 22. a

The tripping of the limit switch L. S. 2 by the leader bar 15 controls a conventional rheostat to the power motors that will lower the speed of the rolls of the four units (pinch feed rolls and straightener, entry table, tank and run-out table) to cause the stock S to feed temrarily at a reduced speed, for example at about 100 P. M. (feet per minute) from the previous speed for example of 200 F. P. M. which may be employed in conveying the leader bar 15 attached to stock S through the treating units. The reason for reducing the speed at this time is so that the leader bar can be conveniently handled on the run out table without damage to any of the run-out table mechanisms. When the leader bar 15 has advanced onto the run-out table it passes between one of the regular run-out table rolls 21 and a trip roll 23a immediately thereabove of a trip roll unit 23 which will cause the leader .bar catch to be released from the strip S. The trip roll 23a is mounted in a block 24 vertically movable in a frame 25 mounted on run-out table 22. The block 24 is movable against the influence of a coil spring 26 and is vertically adjustable in frame 25 as by means of an adjusting screw 27 for reasons as will appear later.

As soon as the leader bar 15 passes through the trip unit 23 it contacts a limit switch L. S. 3 located adjacent the tripunit 23 and which switch controls a clutch unit C (later described in connection with Fig. 13) that will speed up the rolls 21 of the run-out table 22 at a 2 to 1 ratio relative to the rolls 17 of the tank 16. Thus if the rolls of the tank are running at 100 F. P. M. the rolls of the run-out table will operate at 200 F. P. M. This is forthe purpose of advancing the leader bar ahead of the stock a suflicient distance so as to remove it from the table without interference with the advancing stock.

When the leader bar arrives at the right end of the run-out table it will contact a stop bar 28 on a buffer unit 29 so as to'dispose said leader bar directly above a lift-arm unit 30. The latter unit may be actuated by a limit switch L. S. 4 located immediately ahead of the stop bar 28 in order to deposit the leader bar on an inclined guide rail 31 where it will be directed either by gravity or by suitable power-drive means back to the starting end of the machine in a manner to be more fully explained in connection with description of the liftarm unit.

Leader bar The details of the leader bar 15 are shown in Figs. 6, 7 and 8 and consists of a reticulated frame 32 of rectangular shape having a pair of longitudinal ribs 33 adjacent its sides, and another pair of spaced ribs 34 running lengthwise of the frame 32 adjacent its center. Pivotally mounted between the center ribs as at 35 is an elongated clamp lever 36 that has a clamping jaw 37 disposed adjacent the tail end of the leader bar, which jaw cooperates with a dog tooth 38 formed on a part of the frame 32 and between which the strip material S is clamped (see Fig. 8 Clamp lever 36 extends on the other side of its pivot 35 in an upwardly inclined direction 36a and then downwardly at 36b and terminating in a catch nose 36c. The clamp lever 36 is urged in a counterclockwise direction about its pivot 35 by a pair of compression coil springs 36d located between said lever 36 and a cross bar 39 on frame 32, to normally hold the clamping jaw 37 against the dog tooth 38 and grab the strip material S therebetween. In order to hold the clamping jaw 37 in stock-releasing position the catch nose 360 is normally caught underneath a lock lever 40 pivoted at 41 in the frame 32 and located transversely of the center ribs 34. The lock lever 40 is urged in a clockwise direction against a stop shoulder 42 in frame 32 by a tension spring 42::

(see Fig. 6 The lock bar 40 is formed with a camsurface 40a in line with the catch nose 360 for reasons as will appear later.

For the purpose of conveying the leader bar back to its starting position on guide rail 31 a pair of brackets 43 are attached to one side of the frame 32, each bracket 43 supporting a sheave 44. In order to provide a sulficient flexibleness for the sheaves 44 relative to the leader' bar frame 32 so that the sheaves will not bind on riding the curves in the guide rail 31, a special mount for the sheaves 44 is shown in Figs. 9, l0 and 11. As here shown each bracket 43 is provided with a pair of spaced extensions 45 between which is mounted a spindle block 46 having pivotal engagement on a vertical pivot post 47 threaded into bracket 43. The block 46 is formed with a lateral spindle 46a upon which the sheave 44 rotates. Also mounted on the post 47 and above the spindle block 46 is a yoke 48 having oppositely extending pins 49 to which coil springs 50 are attached having their opposite ends fixed to pins 51'projecting from the edge of the brackets 43. The lower end of the block 46 has a beveled surface 46b that engages a complemental beveled surface 52 on bracket 43. These beveled surfaces are normally abutted against each other as shown in Fig. 10 by the force of the springs 50 for the pu ose of holding the sheaves 44 in a stable and parallel position to the leader bar frame 32 when the leader bar is passing through the treating units. When the leader bar is mounted upon the guide rail 31 the weight of said leader bar will cause the block 46 and yoke 48 to move upwardly on post 47 to a stop position where the yoke 48 abuts the head 47a on post 47 as seen in Fig. 11 and thus removing the beveled surface 46b from the beveled surface 52. In this position the spindle hlock is free to pivot on post 47 to allow sheaves 44 to be freely guided along any curves on the return rail 31. The yoke 48 is prevented from twisting by reason of the pins 49 sliding in notches 45a provided in the upper ends of extensions 45, see Fig. 10.

Pinch feed rolls and control As stated heretofore a pinch feed roll unit 20 is located adjacent the exit end of the treating unit 16, and it is necessary at certain times to have the rolls of the feed roll unit to be spaced apart so as to permit an unobstructed passage for the leader bar and immediately thereafter to have the rolls brought together against the stock S to feed the latter after the leader bar has been released therefrom. Fig. 12 shows the details of the pinch roll unit 20 and consists of a support frame 55 mounted on the run-out table 22. A lower roll 56 is journaled in the frame 55 in line with the rolls 21 of the run-out table. An upper roll 57 is journaled in a bearing bracket 58 having vertical sliding engagement in frame 55. In order to space the upper roll 57 from lower roll 56 a pair of links 59 connect the opposite ends of the bracket 58 to a pair of levers 60 pivoted on a pair of lugs 61 depending from the upper part of the support frame, 55. The adjacent ends of the levers 60 have bearing engagement in a plunger 62 operating in an air cylinder 63 on frame 55. The air cylinder 63 is operated from a valve 64 under the control of a solenoid 65 which in turn is also controlled by the limit switch L. S. 3 previously described as controlling the difierential clutch unit C.

This pinch feed roll 20 is to be used particularly in cases where the strip material S is of relatively thin gauge and not of suflicient weight of its own to be carried through on the power-driven rolls of the treating unit 16. In cases where a thick gauge and heavv strip is being used the pinch feed roll unit may not be needed. It will, however, be automatically set into motion after the leader 'bar trips L. S. 3 and then the operator can raise the upper roll 57 from his control board by any conventional control mechanism if there is no need for this pinch feed roll unit. Y

The leader bar 15, during its passage through the trip roll unit 23, will cause the inclined end 36b of the clamp lever 36 to cam against the upper roll 23a and press said lever downwardly against the influence of the springs 36d opening up clamping jaw 37 and thus releasing the leader bar 15 from the stock S. In the act of tripping the lever 36, catch nose 36c will ride downwardly on the cam surface 40a of the lock lever 40 swinging the latter to one side until the nose 360 is positioned underneath the lever 40 whereupon the latter will pivot under the influence of the spring 42a to lie above s aid nose 36c and hold the clamp lever 36 in ope! position during its continued travel thereon and back to starting position. The leader bar will be tripped by the unit 23 to release the stock substantially about the same time that the feedroll unit 20 is operated to grip and pull the stock S through the treating units.

As previously explained the trip roll 23a is ad ustably mounted in unit 23 so as to be raised or lowered 111 order to assure that the roll 23a can be positioned to contact the lever 36 in releasing the leader bar 15 from the stock S.

Leader bar stop and elevator unit As previously explained the leader bar is propelled along the run-out table 22 at a relatively higher speed than the strip upon being released therefrom so as to have ample time to clear it out of the path of the moving stock S. The mechanisms for stopping and picking up the leader bar are best shown in Figs. 3 and 4. As the leader bar 15 advances to the end of table 22 it will be abruptly stopped by striking against the stop bar 28 of the bufier unit 29 wherein said bar 28 is normally positioned in line with the path of said leader bar. The bar 28 is supported on an arm 67 having its mid portion pivoted to a link 68 which in turn is pivoted to the table 21 at 69. The lower end of arm 67 is pivoted to a clev s 70 on one end of a piston 71 operating in a cushion air cylinder 72. The air cylinder is pivoted in a bracket 73 supported on a pedestal 74. The mid portion of l nk 68 is connected to one end of a vertical link 75 having ts opposite lower end pivoted to a horizontal link 76 p voted on pedestal 74. The opposite end of link 76 is p voted to an upright arm 77 carrying a roller 78 on its upper end. I

As previously explained when the leader bar 15 15 n stopped position on table 22 it is disposed above a pair of lift arms 80 having extended portions 80a that lie crosswise of the table 22 slightly below the rolls 21 (see Figs. 3 and 4). The arms 80 are made rigid to the opposite ends of a shaft 81 journaled in bearings 82 on a frame 83 located in back of table 22. In order to elevate the arms 80 a crank lever 84 is secured to shaft 81 and has its free end connected to a piston rod 85 operating from a piston 86 pivotally mounted in frame 83.

Located ahead of the stop bar 28 is a limit switch L. S. 4 that is operated by the leader bar 15. This limit switch L. S. 4 through a suitable solenoid-controlled valve operates the cylinder 86 that will raise the arms 80 to the dotted line position shown in Fig. 4 and lifting the leader bar 15 off of the table 22 out of the path of the advancing stock S. As the arms are being raised the leader bar will slip down the arm extension 80a by gravity and come to rest against a stop member or catch shoulder 80b fixed on arm extension 80a.

From Fig. 3 it is to be noted that the weight of the stop bar 28 and its associated linkage mechanism is counterbalanced by the weight of the lifting arms 80 when the right one rests against the roller 78 on arm 77. The purpose of this is to assure that the stop bar 28 will be raised to a position above the top of the rolls 21 and in line with the traveling leader bar 28 when the arms 80 are down. As soon as the leader bar is lifted by the arms 80 the stop bar 28 will drop to a position out of the path of the advancing stock by reason of its overbalanced weight. The drop position of the stop bar 28 may be controlled as by a lug 74a positioned on pedestal 74 in line with link 76 and serving to limit the clock-wise movement of said link.

When the arms 80 are in full elevated position the sheaves 44 of the leader bar will be disposed above and in line with the hinging section 31a of the guide rail 31. To raise the leader bar off of the arms 80 and catch shoulders 80b the right end of the hinging rail 31a is elevated a slight distance by a hydraulic mechanism now to be explained. As noted in Figs. 3 and 4 in line with the right arm 80 of the lifting unit is positioned a valve.

87 mounted on a bracket 88 rising above frame 83. When this right arm 80 reaches its uppermost position it will contact a valve 87 and open a fluid line 89 leading to a hydraulic cylinder 90 having a pivotal mount on a standard 91 at the end of the feed-out table 22. A piston 92 operating in cylinder 90 is connected to the free end of the rail extension 31a opposite from the hinge 31b, and when valve 87 is opened the piston 92 will elevate the hinging rail 31a to the dotted line position of Fig. 3 and at the same time causing the rail 31:: to engage the sheaves 44 and lift the leader bar 15 off the arms 80 and shoulder 8%. Also the elevated position of the hinging rail 310 will start the leader bar 15 to move by gravity back to the starting end of the machine.

'In order'to assure that the leader bar 15 will quickly move away and clear itself from the support arms in its start back on the rail 31a, the right end of said rail has a pair of rollers 93 attached thereto that operate in a pair of offset grooves 94 provided in a cam box 95 mounted on a standard 91 (see Fig. 14). It will be noted from Fig. 14 that the upper offset position of the grooves 94 is such that the rail 31a will be swung to the rear dui'igg its upward hinging action relative to the stationary rai Leader bar elevating unit.

The leader bar 15 is returned via guide rail 31 to a position directly in back of the entry table 14. Here the guide rail 31 is supported on a standard 96 designed to support the leader bar 15 at rest in a depending position as shown in Fig. 5. The leader bar on its return travel is brought to a stop by striking a butter block 97 on standard 96. 1

-In order to lift the leader bar from the standard 96 onto the entry table 14 a hydraulic lift mechanism is built into said table 14. This mechanism consists of a pair of lift arms 98 keyed to a shaft 99 journaled in suitable bearings 100 on the entry table 14. The arms 98 are constructed with ofiset brackets 101 against which the leader bar rests when being raised onto table 14. The arms 98 are operated by a cylinder 102 pivoted on table 14, the cylinder having a piston rod 103 connected to a lever 104 secured to one of the arms 98 adjacent the shaft 99. In the act of elevating the leader bar it will be guided over a pair of sector blocks 105 secured to table 14 and onto the edges of a pair of skid plates 106 alined with said sector blocks 105.

During the period when the leader bar is being raised onto table 14 the edges of the skid plates 106 will be disposed above the plane of rolls 13 in dotted position as shown in Fig. 5. This is in order to protect the rolls by not dropping the leader bar directly thereupon. The skid plates 106 are held in said elevated position by a pair of hell cranks 107 pivoted on table 14 and having arms 107a connected to said skid plates. The foremost bell cranks 107 have relatively short depending arms 107b which are connected to links 108 which in turn are connected to the intermediate section of longer depending arms 107s of the rearmost bell cranks. Rollers 109 are pivoted on the free ends of arms 1070 and engage cams 110 keyed to the shaft 99. The shape of the cams 110 is such that when the lift arms 98 are being raised the skid plates 106 will be elevated above the rolls 13 to receive the leader bar 15, and when the arms 98 are returned to pickup position the skid plates will be lowered to the full line position of Fig. 5 and deposit the leader bar upon the entry table rolls 13. It is to be understood that the cylinder 102 is controlled from a panel board by the operator when the leader bar 15 is needed to direct a new strip of stock S through the treating units and when it is desired to return the lift arms to loading position preliminary to the operation of attaching the leader bar to the stock.

Difierenlial speed clutch As described heretofore it is necessary at times to r erate the speed of the rolls 17 in the treating tank at a slower speed than the rolls 21 of the run-out table 22 at approximately a 2 to 1 ratio. In order to obtain this difference in speed between the two sets of rolls a conventional two-way clutch unit C with sprocket and chaindrive arrangement may be employed such as disclosed in Fig. 13. As here shown the last roll 17a of the tank 16 is mounted on a shaft 111 that extends through the back wall of the tank. On the shaft outside of the tank is mounted a sprocket wheel 112 to freely rotate thereon and having a clutch collar 113 attached thereto. Another sprocket wheel 114 which is about twice the size of the wheel 112 is mounted to freely rotate upon the outer end of shaft 111 and is likewise provided with a clutch 116 may be moved from one sprocket to the other by a crank lever 117 suitably pivoted to the machines which lever in turn may be operated by a solenoid-con- I trolled cylinder 118 under the control of limit switch L. S. 3. k

The first roll 21a in the series of rolls -21 of the runout table 22 is mounted on a shaft 119 extending to the rear of said table and provided with two sprocket wheels 120 and 121 of equal size and keyed to said shaft 119. The sprocket wheel 112 drives sprocket wheel 120 through chain 122 and the sprocket wheel 114 drives sprocket wheel 121 through chain 123. The sprocket wheels 120 and 121 are of the same size as sprocket wheel 112 and only one-half the size of the sprocket wheel 114, the latter two wheels therefore establishing the -2 to 1 speed ratio between the rolls of the run-out table 22 and the rolls of the treating unit 16.

Each of the rolls 21 in the run-out table 22 are provided with sprocket wheels 124 and a common chain 125 to all of said wheels 124 and said chain 125 may be driven from a suitable source of power such as an electric motor.

The rolls 17 in the treating unit 16 are likewise each provided with sprocket wheels 126 and may be interconnected by a common chain 127 or a series of smaller chains. It is also to be understood that the rolls 13 of the entry table may be driven by the treating unit chain 127 inasmuch as the rolls 13 of the entry table can always operate at the same speed as the rolls 17 of the treating unit.

Operation of machine A brief description of how the machine operates will here be given. A roll of sheet or strip stock S will be placed in the pay-off unit 10. From a control panel the operator will energize the cylinder 102 of the entry table unit and lift the leader bar 011 of the guide rail 31 and onto the entry table 14. The pay-01f .unit 10 will then be jogged about to slowly unwind the roll of stock and direct the leading end of the strip S through the pinch rolls 1'1 and through the straightener rolls 12 onto the entry table 14 to a position where the leading end of the stock will be disposed between the clamplng jaw 37 and dog-tooth 38 of said leader bar. The operator will then move the lock lever 40 of the leader bar in a counterclockwise direction as viewed in Fig. 6, whereupon the clamp lever 36 will be released to swing around its pivot 35 under influence of springs 36d and rigidly clamp the stock S between the jaw 37 and tooth 38. The rolls of the first pinch feed rolls and straightener, entry table, treating tanks and run-out table will be set into motion from the control panel whereupon the leader bar will guide and draw stock through the several treating units. In leading the stock S through the machine with the leader bar it can be reasonably speeded up so that it travels about 200 F. P. M.

As soon as the leader bar emerges from the last treating tank 16 it'contacts limit switch L. S. 2 that slows the power motors so that rolls of the four units, pinch feed rolls and straightener, entry table, tanks and run-out table will operate to feedthe stock at about 100 F. P. M. The leader bar will immediately pass through the pinch feed roll unit and contact the trip roll 23a whereupon the leader bar will be released from the stock S. Simultaneously with the releasing of the leader bar from the stock S. said leaderbar will contact the limit switch L. S. 3 that controls the feed roll unit 20 to bring the pinch rolls 56 and 57 together for the purpose of drawing the stock through the machine. As previously explained this unit 20 may only be necessary when the stock is relatively light and not of sutficient weight to carry itself through the machine. In the treating of heavy stock the rolls of the unit 20 may be immediately restored to a separated state by the operator from the control panel.

The limit switch L. S. 3 also controls the differential clutch-control unit C and will at this time throw the clutch 11-6 to the position shown in Fig. 13 to engage the large sprocket 114 wherein the rolls of the run-out table will be speeded up at a 2 to 1 ratio relative to the tank rolls or about 200 F. P. M. With the rolls of the runout table operating at a 2 to 1 ratio to the rolls of the treating units. the leader bar will be advanced ahead of the leading end of the stock to the end of said table where it will strike the stop bar 28 of the buffer unit 29 and brought to a stop in which position ill leader bar will be positioned above the arms 80 of the lift unit 30. Immediately before the leader bar strikes the stop bar 28 it will contact the limit switch L. S. 4 which controls the lift unit and cause the arms to lift the leader bar off the run-out table onto the hinging rail 310. During the raising of arms 80 one of said arms will contact the fluid valve 87 and operate the cylinder 90 which in turn will elevate the right end of the hinging rail 31a and start the leader bar 15 back to its starting position in back of the entry table 14.

The limit switch L. S. 4 also controls the differential clutch unit C that restores the rolls of the run-out table and the treating unit to a 1 to 1 ratio thus dropping the speed of the run-out table rolls to F. P. M. From now on the speed of sending the stock through the machine will be-under the control of the operator.

When the tail end of the stock S leaves the straightening unit 12 it will trip a limit switch L. S. I placed adjacent thereto that operates to automatically control the speed of the main drive motor so that all units will be operated to slow the speed of the stock to 200 F. P. M. The reduced speed control is necessary at this time to prevent the tail end of the stock S from whipping around too severely while passing through the tanks of the several treating units.

The treated stock may be conveniently coiled up by a coiling unit or blocker 128 located at the right end of the run-out table 22 as shown in Figs. 1 and 2.

In the present embodiment there is shown a series of limit switches as being the automatic control means of the several units of the mechanism but in practice I have made use of photo-electric cells to accomplish the same purpose.

Whi e I have shown and described a specific embodiment of the invention, it will be understood that many changes and alterations may be made therein without departing from the scope of the invention as defined by the following claims.

I claim:

1. A method of conducting strip material through a treating unit while supported on a plurality of powerdriven rolls, comprising attaching to one end of the strip material a strip leader member, propelling said member through said unit by said rolls, removing said member from said strip after it has passed through said unit and returning it to entrance end of said unit without interrupting the movement of this strip material in said unit.

2. A method of conducting strip material through a treating unit while supported on a plurality of powerdriven rolls, comprising attaching to one end of the strip material a strip leader member, propelling said member through said unit by said rolls, removing said member from said strip after it has passed through said unit, advancing said member ahead of the travelling material and then removing the member from the path of said material and returning it to the entrance end of said unit without interrupting the movement of said strip material in said unit.

3. In an apparatus for continuously drawing strip material through a treating unit, comprising an entry table and a run-out table located at opposite ends of said unit, power-driven rolls on said tables and in said unit, a leader bar supported on said rolls and engaged thereby to be propelled through said unit, means for attaching said bar tosaid strip material at said entry table end, and means for automatically releasing said-leader bar from said material upon reaching said run-out table.

4. In an apparatus for continuously drawing strip material through a treating unit, comprising an entry table and a run-out table located at opposite ends of said unit, power-driven rolls on said tables and in said unit, a leader bar propelled by said rolls, means for attaching said bar to said strip material, said-bar being of a weight to draw said material through said unit, means for automatically releasing said leader bar from said material upon reaching said run-out table, and means for returning said leader bar from said run-out table to said entry table after it has been released from said material.

5. In an apparatus for continuously drawing strip material through a treating unit comprising an entry table and a run-out table located at opposite ends of said unit, power-driven rolls on said tables and in said unit, a leader bar having means for releasably engaging one end of the strip material, said bar being of a weight to draw said material through said unit by frictional contact with said rolls, means for automatically releasing said leader bar from said material upon its exit from said unit, means for removing said leader bar from said run-out table out of the path of the advancing material, means for returning said leader bar to the entry table, and means for continuing the movement of said stock through said unit after the release of said leader bar.

6. In an apparatus for continuously drawing strip material through a treating unit comprising an entry table and a run-out table located at opposite ends of said unit, power-driven rolls on said tables and in said unit, a leader bar having means for releasably engaging one end of the strip material, said bar being of a weight to draw said material through said unit on being propelled along by said rolls, a set of pinch feed rolls positioned adjacent the exit end of said unit having means to hold the rolls in spaced relationship to permit passage of the leader bar therethrough, means for releasing said leader bar from said strip material after it has passed through said pinch feed rolls, and means actuated by said leader bar to bring said pinch feed rolls together against opposite sides of the strip material for the purpose of continuing the drawing of said material through said unit after the leader bar has been released.

7. In an apparatus for continuously drawing strip material through a treating unit comprising an entry table and a run-out table located at opposite ends of said unit, power-driven rolls on said tables and in said unit, a leader bar having means for releasably engaging one end of the strip material, said bar being of a weight to draw said material through said unit on being propelled along by said rolls, means for automatically releasing said leader bar from said material upon its exit from said unit, means for speeding up the rolls on said run-out table to advance the leader bar beyond the advancing end of said material, and means for stopping said leader bar on said run-out table and removing said bar from said table out of the path of the advancing stock.

References Cited in the file of this patent UNITED STATES PATENTS 1,256,290 Blondes Feb. 12, 1918 1,616,121 Gruber Feb. 1, 1927 1,623,537 Hill Apr. 5, 1927 1,855,477 Emery Apr. 26, 1932 2,166,583 Critten July 18, 1939 2,234,815 Wood Mar. 11, 1941 2,314,369 Reed Mar. 23, 1943 2,424,052 Pratt July 15, 1947 2,488,141 Pratt Nov. 15, 1949 2,581,026 Keller Jan. 1, 1952 

1. A METHOD OF CONDUCTING STRIP MATERIAL THROUGH A TREATING UNIT WHILE SUPPORTED ON A PLURALITY OF POWERDRIVEN ROLLS, COMPRISING ATTACHING TO ONE END OF THE STRIP MATERIAL A STRIP LEADER MEMBER, PROPELLING SAID MEMBER THROUGH SAID UNIT BY SAID ROLLS, REMOVING SAID MEMBER FROM SAID STRIP AFTER IT HAS PASSED THROUGH SAID UNIT AND RETURING IT TO ENTRANCE END OF SAID UNIT WITHOUT INTERRUPTING THE MOVEMENT OF THIS STRIP MATERIAL IN SAID UNIT.
 3. IN AN APPARATUS FOR CONTINUOUSLY DRAWING STRIP MATERIAL THROUGH A TREATING UNIT, COMPRISING AN ENTRY TABLE AND A RUN-OUT TABLE LOCATED AT OPPOSITE ENDS OF SAID UNIT, POWER-DRIVEN ROLLS ON SAID TABLES AND IN SAID UNIT, A LEADER BAR SUPPORTED ON SAID ROLLS AND ENGAGED THEREBY TO BE PROPELLED THROUGH SAID UNIT, MEANS FOR ATTACHING SAID BAR TO SAID STRIP MATERIAL AT SAID ENTRY TABLE END, AND MEANS FOR AUTOMATICALLY RELEASING SAID LEADER BAR FROM SAID MATERIAL UPON UPON REACHING SAID RUN-OUT TABLE. 